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Thermo-magnetic characterization of phase transitions in a Ni-Mn-In metamagnetic shape memory alloy
- Source :
- idUS: Depósito de Investigación de la Universidad de Sevilla, Universidad de Sevilla (US), idUS. Depósito de Investigación de la Universidad de Sevilla, instname, Digital.CSIC. Repositorio Institucional del CSIC
- Publication Year :
- 2021
-
Abstract
- The partially overlapped ferroelastic/martensitic and para-ferromagnetic phase transitions of a Ni$_{50.53}$Mn${33.65}$In$_{15.82}$ metamagnetic shape memory alloy have been studied from calorimetric, magnetic and acoustic emission measurement. We have taken advantage of the existence of thermal hysteresis of the first order ferroelastic/martensitic phase transition ($\sim2.5$K) to discriminate the latent heat contribution $\Delta$Ht = 7.21(15) kJ/kg and the specific heat contribution $\Delta$Hc = 216(1) J/kg to the total excess enthalpy of the phase transition. The specific heat was found to follow a step-like behavior at this phase transition. The intermittent dynamics of the ferroelastic/martensitic transition has been characterized as a series of avalanches detected both from acoustic emission and calorimetric measurements. The energy distribution of these avalanche events was found to follow a power law with a characteristic energy exponent $\epsilon\sim2$ which is in agreement with the expected value for a system undergoing a symmetry change from cubic to monoclinic. Finally, the critical behavior of the para-ferromagnetic austenite phase transition that takes place at $\sim 311$K has been studied from the behavior of the specific heat. A critical exponent $\alpha\sim0.09$ has been obtained, which has been shown to be in agreement with previous values reported for Ni-Mn-Ga alloys but different from the critical divergence reported for pure Ni.<br />Comment: 18 pages, 11 figures
- Subjects :
- Austenite
heat capacity
Phase transition
Condensed Matter - Materials Science
Materials science
Mechanical Engineering
Enthalpy
Metals and Alloys
Thermodynamics
Materials Science (cond-mat.mtrl-sci)
FOS: Physical sciences
Shape-memory alloy
magnetization
Power law
Heat capacity
metals and alloys
Magnetization
Condensed Matter::Materials Science
Mechanics of Materials
kinetics
Latent heat
Materials Chemistry
entropy
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- idUS: Depósito de Investigación de la Universidad de Sevilla, Universidad de Sevilla (US), idUS. Depósito de Investigación de la Universidad de Sevilla, instname, Digital.CSIC. Repositorio Institucional del CSIC
- Accession number :
- edsair.doi.dedup.....cfc2b4be5ca20eee9091160a8472d234